<VV> No Reverse Gear

[Brown, Douglas T CIV NAVAIR DEPT]

I pulled my 65 out yesterday from where I had backed it in last week and found I have no reverse.  I had trouble finding reverse when I bought the car last month and have already gone through the usual adjustments.  The coupler has minimal play, Clark's bronze bushings were already installed, and I found one of the set screws missing in the quick-shift extension.  After replacing it, reverse worked...for a while, though still difficult to get sometimes.  

Last night I tried tightening the bolts holding the shifter to the floor, thinking I may have left them too loose, and it only made everything stiff and immobile.  So I took it apart and replaced the upper spacer, which was gone, and used white grease on the upper and lower spacers.  I tightened it back to where there was no slop but had smooth, easy operation.  I still had no reverse.  Shifter will not move to the left past the 1-2 side of the pattern in neutral.

I then disconnected the coupling from the shifter shaft and clamped a vise-grip on to the shaft.  Even with the linkage disconnected, I cannot get the shaft to rotate to the position to the left of the "H" pattern where reverse would be.  I looked in the chassis shop manual and found in the description of the 4-speed trans that there is a spring loaded plunger that prevents accidentally shifting into reverse.  There was no further discussion of this part.  Could this plunger be stuck, not allowing the shift finger to rotate over to the reverse gate on the 1-2 shift fork?  Or is something else broken?  Is there a way to check it, and correct it without removing and disassembling the whole transmission?  Looking for some sage advice from those who have BTDT.  Thanks.

Toby Brown
San Diego CC